Q: what causes the awd light to stay on with a 2011 infiniti g25x

If the AWD warning light is on all the time, that means a fault of some sort has been detected, likely in the control system or sensors but there are mechanical possibilities, too. Your vehicle has an onboard diagnostic system (referred to as OBD-II) that stores trouble codes that "set". The AWD warning light means that such codes have "set" and can be downloaded by the mechanic. If you request a warning light diagnostic - AWD the responding certified mechanic will read the codes and perform the required diagnostic to point whatever the fault is. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.